This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 10 |
| 5 | 33 |
| 6 | 147 |
| 7 | 620 |
| 8 | 2821 |
| 9 | 12942 |
| 10 | 60639 |
| 11 | 286190 |
| 12 | 1364621 |
| 13 | 6545430 |
| 14 | 31586358 |
| 15 | 153143956 |
| 16 | 745700845 |
| 17 | 3644379397 |
| 18 | 17869651166 |
| 19 | 87877879487 |
| 20 | 433301253231 |
| 21 | 2141584454057 |
| 22 | 10607707971062 |
| 23 | 52646117638427 |
| 24 | 261756764824964 |
| 25 | 1303625908234997 |
| 26 | 6502430891223011 |
| 27 | 32480041218465452 |
| 28 | 162454295068924189 |
| 29 | 813541940383789255 |
| 30 | 4078750395194965720 |